Analysis of temperature-dependent current transport mechanism in Cu/n-type Ge Schottky junction

Abstract

We employed oxygen plasma treatment to improve the electrical properties in Cu/n-type Ge Schottky junctions and investigated temperature dependent current transport mechanism in the temperature range of 100-300 K. The Schottky barrier height increased commensurate with increasing temperature, which was attributed to barrier inhomogeneity. The inhomogeneity of the barrier was represented by a double Gaussian distribution, each one prevailing in a distinct temperature range: a high-temperature range from 220 to 300 K and a low-temperature range from 100 to 180 K. Modified Richardson plots revealed a Richardson constant of 160.0 Acm(-2) K-2 for the high-temperature region (220-300 K), which is comparable to the theoretical value of 140.0 Acm(-2) K-2 for n-type Ge. Reverse current analysis revealed that Poole Frenkel and Schottky emissions were dominant in the lower and higher voltage regions, respectively. (C) 2015 Elsevier Ltd. All rights reserved.